I am trying to setup a serial connection through a serial expander chip. This chip is the SC16IS752 and ads the ports: ttySC0, ttySC1 and so forth.

I succeed in adding generic sensors, like a GPS sensor and I can connect to an Arduino Nano. Sometimes I need to lower the baudrate to 4800 or 9600, so it will receive communication. However the chip is supposed to be able to communicate 115200 baud.

When trying to use the script, I adjust it as follows:

serial_port.baudrate = 4800
serial_port.port = '/dev/ttySC3'

The baudrate I am changing each time, to test if it wil make the script work.
The serial port I know is correct, because when opening the script the LED's will blink to the right port.

I cannot get the script to work, I've tried numerous baudrates but I have not yet succeeded.
I already have ttyAMA0 default port working on a Quectel chip so I know I have configured serial connection in boot/config.txt correctly.

The only thing I have not done is to add the lin core_freq=250[nbsp]
I understand this line is only needed if using bluetooth, however I am using a compute module which doesn't have bluetooth.

Hope somone may be able to help me!

Jamos Tan

24.02.21 12:55


thank you for your message. The StromPi communicates at a baudrate of 38400. Using a baudrate that is higher or lower than that, is sadly not going to work. You also wrote that you need to adjust the baudrate to a relatively low number like 4800 or 9600 to receive any communication at all. Maybe the resistance of the connectors is too high to allow a faster communication.

Best regards

Niklas Tritschler

01.03.21 15:18